var Utils = {};
Utils.historyInit = function () {
    var state = {
        title: window.document.title,
        url: window.location.href
    };
    window.history.pushState(state, state.title, state.url);
}
Utils.historyBack = function (callback) {
    Utils.historyInit();
    window.addEventListener("popstate", function(e) {
        if (typeof callback == 'undefined') {
            window.location.href = window.document.referrer;
        } else {
            callback();
        }
    }, false);
};
Utils.getRequestParam  = function () {
    var urs=window.location.search;
    var strs=urs.substring(1);
    var silp=strs.split('&');
    var res={};
    for (var i=0;i<silp.length;i++){
        res[silp[i].split("=")[0]]=silp[i].split("=")[1];
    }
    return res;
};